Lens mounting device and projector

Abstract

To provide a lens mounting apparatus and a projector.SOLUTION: A lens mounting apparatus includes a base portion having an opening into which a lens having a connection portion is inserted and attached, an annular frame having a notch portion provided on a part of an outer periphery, a socket electrically connected to the connection portion of the lens, and a first elastic member provided to urge the socket from the outer periphery side toward a center of the annular frame. The annular frame is rotatably attached to the base portion. The annular frame is configured to fix the lens inserted and attached into the base portion by rotating the annular frame in one direction by a predetermined angle. When the annular frame does not fix the lens, the notch portion does not face the socket. When the annular frame fixes the lens, the notch portion faces the socket, and the socket is electrically connected to the connection portion of the lens by an urging force of the first elastic member.SELECTED DRAWING: Figure 1

Description

Technical Field

[0008]

[0001] The present invention relates to a lens mounting device and a projector including the lens mounting device.

Background Art

[0002] When attaching a lens to a camera, a projector, or the like, it is necessary to electrically connect the lens contacts of the lens and the socket contacts of the socket mounted on the camera, projector, or the like, and to fix the lens to the camera, projector, or the like.

[0003] As such a lens mounting device, Patent Document 1 discloses the following configuration.

[0004] In Patent Document 1, in order to prevent the lens from being misattached to the camera by electrically connecting the lens contacts and the socket contacts well, after inserting the lens into the camera, the lens is rotated to electrically connect the lens contacts and the socket contacts.

[0005] As a result, the camera of Patent Document 1 has the advantages of a small socket size and low cost.

[0006] <00​​​​​​​​​​​In addition to the rotary mounting structure disclosed in Patent Document 1, the following direct insertion type mounting structure is also disclosed in the prior art as a lens mounting device.

[0010] Specifically, in a direct-insertion type lens mounting structure, after inserting the lens into a camera or projector, the lens contacts and socket contacts are directly electrically connected without rotating the lens.

[0011] Thus, since there is no need to rotate the lens after insertion, the lens mounting operation is convenient. Furthermore, the rate of poor contact at the contact points is reduced after lens insertion.

[0012] However, the conventional technologies described above have the following technical challenges.

[0013] Because the socket has a large volume, the space available for installing the lens mount becomes limited.

[0014] Furthermore, because the socket needs to move freely within a confined space so that its position does not affect the lens positioning, the cost of the socket increases. [Prior art documents] [Patent Documents]

[0015] [Patent Document 1] Japanese Patent Publication No. 2012-155290 [Overview of the Initiative] [Problems that the invention aims to solve]

[0016] The present invention has been made to solve the above-mentioned technical problems, and aims to provide a lens mounting device that can reduce the volume of the socket, suppress poor contact of the socket contacts, and improve the ease of mounting the lens, and a projector equipped with the lens mounting device. [Means for solving the problem]

[0017] To achieve the above objective, the lens mounting device according to the present invention comprises a base portion having an opening into which a lens having a connecting portion is inserted, an annular frame having a notch provided on a part of its outer circumference, a socket electrically connected to the connecting portion of the lens, and a first elastic member provided to bias the socket from the outer circumference toward the center of the annular frame. The annular frame is rotatably mounted on the base portion. By rotating the annular frame by a predetermined angle in one direction, the annular frame is configured to fix the lens inserted on the base portion. When the annular frame does not fix the lens, the notch does not face the socket. When the annular frame fixes the lens, the notch faces the socket, and the socket is electrically connected to the connecting portion of the lens by the biasing force of the first elastic member. [Effects of the Invention]

[0018] According to the lens mounting device of the present invention, the first elastic member is provided to bias the socket from the outer circumference of the annular frame toward the center, i.e., toward the radial center. As a result, the effective stroke of the socket contact, which serves as the connection part of the socket, is increased, and the rate of poor contact at the contact is reduced.

[0019] Furthermore, when inserting the lens, the socket contacts of the socket and the lens contacts (which serve as the connection points for the lens) do not come into contact, thus preventing the socket contacts from being impacted and deforming.

[0020] Furthermore, since the socket does not affect the positioning of the lens, the lens can be precisely positioned.

[0021] Furthermore, since the lens does not need to be rotated after insertion, the lens mounting operation is convenient, and the ease of mounting is improved, especially for heavy lenses.

[0022] Finally, since the socket can move radially, the socket is small in size and low in cost.

Brief Description of the Drawings

[0023] [Figure 1] FIG. 1 is an exploded perspective view of the lens mounting device of the present invention. [Figure 2] FIG. 2 is a plan view of the lens mount in the base portion as viewed from the left side of FIG. 1. [Figure 3] FIG. 3 is a view showing the installation state between the second elastic member and the annular frame body in FIG. 1, (a) is a perspective view, and (b) is a plan view of the second elastic member and the annular frame body as viewed from the left side of FIG. 1. [Figure 4] FIG. 4 is a view showing the state of the socket before the annular frame body is rotated to fix the lens, (a) is a plan view of the annular frame body and the main body in the base portion as viewed from the right side of FIG. 1, and (b) is a view showing a state where the socket contact and the lens contact are not electrically connected. [Figure 5] FIG. 5 is a view showing the state of the socket after the annular frame body is rotated to fix the lens, (a) is a plan view of the annular frame body and the main body in the base portion as viewed from the right side of FIG. 1, and (b) is a view showing a state where the socket contact and the lens contact are electrically connected. [Figure 6A] FIG. 6A is a perspective view of the lens and the annular frame body, showing the state after the annular frame body is rotated to fix the lens. [Figure 6B] FIG. 6B is a view showing the positional relationship between the second elastic member and the convex portion before the annular frame body is rotated to fix the lens, and is a plan view of the annular frame body and the main body in the base portion as viewed from the right side of FIG. 1. [Figure 7] FIG. 7 is a schematic view showing that by rotating the annular frame body, the second elastic member sequentially elastically abuts against the convex portion of the lens to fix the lens. [Figure 8A] FIG. 8A is a schematic view showing that the lens changes from a non-fixed state to a fixed state. [Figure 8B]Figure 8B is a schematic diagram showing the change in position of the second elastic member before and after lens fixation. [Figure 9] Figure 9 is a schematic diagram illustrating the change from a fixed state to an unfixed state of the lens. [Figure 10] Figure 10 is a plan view showing a stopper portion provided on the main body of the base section for limiting the rotation angle of the annular frame. [Figure 11] Figure 11 is a schematic diagram of various embodiments of the notches provided on a part of the outer circumference of the annular frame. [Figure 12] Figure 12 is a plan view of the main part of the projector of the present invention. [Modes for carrying out the invention]

[0024] The structure and function of each part of the present invention will be described in detail below with reference to the drawings. In the following description, the same or equivalent components and structures will be denoted by the same reference numerals to avoid redundant explanations.

[0025] As shown in Figure 1, the lens mounting device of the present invention comprises a base portion 1 having an opening 1a into which a lens 5 (see Figure 6A described later) is inserted, an annular frame 2 having a notch 2a formed by cutting out a part of its outer circumference, a socket 3 electrically connected to a lens contact 5a as a connection part of the lens 5, and a first elastic member (e.g., a spring) 4 provided to bias the socket 3 from the outer circumference of the annular frame 2 toward the center, i.e., toward the radial center. Here, the lens 5 is a projection lens used in a projector described later. Note that the lens is not shown in Figure 1.

[0026] More specifically, as shown in Figure 1, the base portion 1 includes a main body 1b and a lens mount 1c, and the main body 1b and lens mount 1c have openings 1a into which the lens 5 is inserted. The annular frame 2 is provided between the main body 1b and the lens mount 1c, and a recess 2b is formed on the inner circumference of the annular frame 2 through which a protrusion 5b (see Figures 6A and 6B described later) provided on the outer surface of the lens 5 is inserted, and the socket 3 is movably installed on the main body 1b.

[0027] Furthermore, as shown in Figure 2, the lens mount 1c is provided with a groove 1ca that houses the protrusion 5b, which is inserted through the recess 2b of the annular frame 2.

[0028] In other words, while the socket 3 is not moving from the outer circumference of the annular frame 2 toward the center, i.e., toward the radial center, due to the elastic force of the first elastic member 4, the lens 5 is inserted into the base portion 1 from the main body 1b side in Figure 1 via the opening 1a. The convex portion 5b provided on the outer circumference of the lens 5 is inserted through the recess 2b provided on the inner circumference of the annular frame 2, and then houses and engages with the groove 1ca provided on the lens mount 1c, thereby allowing the lens 5 to be smoothly attached to the base portion 1. At this time, the lens contact 5a of the lens 5 and the socket contact 3a of the socket 3 face each other with a gap between them.

[0029] Furthermore, in this invention, the annular frame 2 is rotatably attached to the base portion 1, and the lens 5 inserted into the base portion 1 is fixed by rotating it by a predetermined angle in one direction (for example, clockwise in Figure 4(a)).

[0030] Specifically, as shown in Figures 1 and 3, a second elastic member (e.g., a resilient piece) 6 is provided on the annular frame 2 at a predetermined distance from one end of the recess 2b. This elastic member 6 elastically contacts the convex portion 5b of the lens 5 when the annular frame is rotated in one direction, biasing the lens 5 toward the lens mount 1c on the base portion 1 and fixing the lens 5 in place.

[0031] In Figure 3, one end 6a of the second elastic member 6, which serves as a fixed end, is fixed to the side surface of the annular frame 2 facing the main body 1b with a screw or the like, and the other end 6b of the second elastic member 6, which serves as an elastic end, is inserted through a through hole provided in the annular frame 2 and protrudes from the side surface of the annular frame 2 facing the lens mount 1c. When the annular frame 2 rotates in one direction, the other end 6b elastically contacts the convex portion 5b of the lens 5, biasing the lens 5 toward the lens mount 1c on the base portion 1, thereby fixing the lens 5 in place.

[0032] Of course, the second elastic member 6 of the present invention is not limited to the above embodiment, and for example, the second elastic member 6 may be constructed by fixing an elastic body to the side surface of the annular frame 2 facing the lens mount 1c by means of adhesive or welding.

[0033] The changes in the non-electrically connected state and the electrically connected state between the socket contact 3a and the lens contact 5a of the present invention will be described below with reference to Figures 4 and 5.

[0034] As shown in Figure 4(a), when the annular frame 2 is not rotated clockwise to fix the lens 5, the notch 2a of the annular frame 2 is not in a position facing the socket 3, and the arc portion of the annular frame 2 abuts against the socket 3 so that the socket 3 compresses the first elastic member 4. As a result, as shown in Figure 4(b), the socket contact 3a and the lens contact 5a of the lens 5 inserted into the base portion 1 face each other with a gap between them. In other words, the socket contact 3a and the lens contact 5a are not electrically connected.

[0035] Furthermore, as shown in Figure 5(a), when the annular frame 2 is rotated clockwise, and the other end 6b of the second elastic member 6 elastically contacts the convex portion 5b of the lens 5, biasing and fixing the lens 5 toward the lens mount 1c on the base portion 1, the notch 2a rotates to a position facing the socket 3 as the annular frame 2 rotates, the first elastic member 4 stretches, and biases the socket 3 from the outer circumference of the annular frame 2 toward the center, i.e., toward the radial center. As a result, the socket 3 moves toward the center due to the biasing force of the first elastic member 4 and comes into contact with the lens contact 5a of the lens 5, and as shown in Figure 5(b), the socket contact 3a and the lens contact 5a of the lens 5 inserted into the base portion 1 face each other without any gap between them. That is, the socket contact 3a and the lens contact 5a are electrically connected.

[0036] In other words, in the present invention, when the lens 5 is in an unfixed state and not fixed to the base portion 1, the socket contact 3a and the lens contact 5a are in a non-electrically connected state, but when the lens 5 is in a fixed state and fixed to the base portion 1, the socket contact 3a and the lens contact 5a are in an electrically connected state.

[0037] As a result, in the lens mounting device of the present invention, the first elastic member 4 is provided to bias the socket 3 from the outer circumference of the annular frame 2 toward the center, i.e., toward the radial center. That is, since the socket 3 is movable radially by the biasing force of the first elastic member 4, the effective stroke of the socket contact 3a of the socket 3 is increased, and the rate of poor contact at the contact is reduced.

[0038] Furthermore, when the lens 5 is inserted, the socket contact 3a of the socket 3 and the lens contact 5a of the lens 5 do not come into contact, thus preventing the socket contact 3a of the socket 3 from being subjected to impact and deforming.

[0039] Furthermore, since socket 3 does not affect the positioning of lens 5, the position of lens 5 can be precisely determined.

[0040] Furthermore, since lens 5 does not need to be rotated after insertion, the installation of lens 5 is convenient, and the ease of installation is improved, especially for heavier lenses.

[0041] Finally, because socket 3 is radially movable, the socket is small in size and low in cost.

[0042] Hereinafter, an embodiment in which the lens 5 is fixed to the base part 1 using the annular frame 2 of the present invention will be described with reference to Figures 6A to 8B. In this application, "lens" does not refer to the lens itself as an optical element, but rather to a lens module that is attached to a camera or projector with interchangeable lenses and has metal contacts (connecting parts), as shown in Figure 6A.

[0043] As described above, in this invention, after inserting the lens 5 into the base portion 1, the annular frame 2 is rotated without rotating the lens 5 to fix the lens 5 to the base portion 1.

[0044] Specifically, as described above, the lens 5 is inserted into the base portion 1 from the main body 1b side in Figure 1 via the opening 1a. Figure 6A is a perspective view of the installation state between the lens 5 and the annular frame 2 after the convex portion 5b provided on the outer surface of the lens 5 has passed through the recess 2b provided on the inner circumference of the annular frame 2, and shows the state after the annular frame 2 has been rotated to fix the lens 5.

[0045] In contrast, Figure 6B shows the positional relationship between the second elastic member 6 and the protrusion 5b before the annular frame 2 is rotated to fix the lens 5. Note that in Figure 6B, only the protrusion 5b provided on the outer surface of the lens 5 is schematically shown.

[0046] More specifically, the convex portion 5b of the lens 5, the recess 2b of the annular frame 2, and the second elastic member 6 are provided in corresponding multiple locations. For example, as shown in Figure 6B, there are three corresponding convex portions 5b of the lens 5, three recesses 2b of the annular frame 2, and three second elastic members 6.

[0047] Furthermore, the predetermined distance between one end of each recess 2b (for example, the downstream end in the clockwise direction in Figure 6B) and the corresponding second elastic member 6 (in this embodiment, the other end 6b of the second elastic member 6) is different. That is, distances S1 to S3 are different from each other.

[0048] Preferably, as shown in Figure 6B, the distances S1, S2, and S3 between the other end 6b of the second elastic member 6 and the recess 2b are sequentially increased in a counterclockwise direction. That is, the predetermined distance between one end of each recess 2b and the corresponding other end 6b of each second elastic member 6 is set so that when the annular frame 2 is rotated in one direction (clockwise), the other end 6b of each second elastic member 6 and the corresponding protrusions 5b sequentially come into elastic contact. As a result, when the annular frame 2 is rotated, the other ends 6b of the three second elastic members 6 do not elastically contact the three protrusions 5b simultaneously, but rather sequentially. Therefore, a sudden increase in the resistance experienced when the annular frame 2 is rotated can be prevented, and this resistance can be increased gradually, allowing the annular frame 2 to rotate smoothly and preventing deformation or displacement of the annular frame 2.

[0049] Figure 7 is a schematic diagram showing a state in which, for example, by rotating the annular frame 2 clockwise from the state shown in Figure 6B, the other end 6b of each second elastic member 6 and the corresponding protrusions 5b sequentially come into elastic contact.

[0050] As shown in Figure 6B, the distances S1, S2, and S3 between the other end 6b of the second elastic member 6 and the recess 2b increase sequentially in a counterclockwise direction. Therefore, when the annular frame 2 is rotated clockwise, as shown in Figure 7(a), first, the other end 6b of the second elastic member 6 of the first group begins to elastically contact the corresponding protrusion 5b, and then, as the annular frame 2 rotates, as shown in Figure 7(b), the other end 6b of the second elastic member 6 of the second group begins to elastically contact the corresponding protrusion 5b. Finally, as the annular frame 2 rotates, as shown in Figure 7(c), the other end 6b of the second elastic member 6 of the third group begins to elastically contact the corresponding protrusion 5b. This allows the annular frame 2 to be smoothly rotated by a predetermined angle and the lens 5 to be fixed to the base 1. In other words, the distances S1 to S3 are set so that multiple second elastic members 6 and multiple protrusions 5b sequentially make elastic contact.

[0051] In the above explanation, fixing the lens 5 by rotating the annular frame 2 means, for example, rotating the operating lever 2c (see Figures 1 and 3, etc.) which is located at a different location from where the notch 2a is formed on the outer circumference of the annular frame 2, thereby rotating the annular frame 2 in one direction (clockwise in the above explanation, but of course, it could also be counterclockwise).

[0052] Next, the change from the unfixed state to the fixed state of lens 5 will be explained using Figures 8A and 8B. Figures 8A and 8B are overall perspective views of the lens mounting device including lens 5 of the present invention.

[0053] As described above, Figures 4(a), 5(a), and 6B are plan views of the annular frame 2 and the main body 1b of the base portion 1, respectively, viewed from the right side of Figure 1, whereas Figures 8A and 8B are perspective views of the base portion 1 and the annular frame 2 and other components, viewed from the left side of Figure 1. Therefore, in Figures 8A and 8B, the rotation direction of the annular frame 2 is counterclockwise, unlike the rotation direction described above (i.e., clockwise).

[0054] Figure 8A is a schematic diagram of lens 5 as it changes from an unfixed state to a fixed state.

[0055] In Figure 8A, by rotating the operating lever 2c, for example, counterclockwise, the lens 5 changes from an unfixed state to a fixed state. At the same time, the socket contact 3a of the socket 3 and the lens contact 5a of the lens 5 become electrically connected.

[0056] Furthermore, Figure 8B is a partial perspective view showing the change in position of the second elastic member 6 when the lens 5 changes from an unfixed state to a fixed state. Note that the lens 5 is not shown in Figure 8B in order to explain the change in position of the elastic member 6. As shown in Figure 8B, before the lens 5 is fixed, the other end 6b of the second elastic member 6 does not contact the protrusion 5b of the lens 5 provided in the groove 1ca of the lens mount 1c. However, after the lens 5 is fixed, the other end 6b of the second elastic member 6 contacts the protrusion 5b and fixes the lens 5.

[0057] Next, the change from the fixed state to the unfixed state of lens 5 will be explained using Figure 9. As corresponding to Figure 8A, Figure 9 is an overall perspective view of the lens mounting device including lens 5 of the present invention.

[0058] As described above, in Figure 8A, by rotating the operating lever 2c, for example, counterclockwise, the lens 5 changes from an unfixed state to a fixed state.

[0059] In contrast, to remove lens 5 by switching it from a fixed state to an unfixed state, for example, as shown in Figure 9, the operating lever 2c can be rotated, for example, clockwise. This changes lens 5 from a fixed state to an unfixed state. At the same time, the electrical connection between the socket contact 3a of socket 3 and the lens contact 5a of lens 5 is also released.

[0060] As described above, in the present invention, by rotating the annular frame 2 by a predetermined angle in one direction (clockwise or counterclockwise), the lens 5 inserted into the base portion 1 is fixed, and at the same time, an electrical connection is established between the socket contact 3a and the lens contact 5a. Conversely, by rotating the annular frame 2 by a predetermined angle in the opposite direction (counterclockwise or clockwise), the lens 5 inserted into the base portion 1 is released, and at the same time, the electrical connection between the socket contact 3a and the lens contact 5a is released.

[0061] Furthermore, the stopper portion 1ba that limits the rotation angle of the annular frame 2 of the present invention will be explained with reference to Figure 10.

[0062] In Figure 10, the main body 1b of the base portion 1 is provided with a stopper portion 1ba, which is formed by providing a notch on the inner circumference of the main body 1b. Furthermore, as shown in Figures 1 and 3, a protrusion 2d is provided on the outer circumference of the annular frame 2 at a location different from where the notch 2a and the operating lever 2c are provided. When this protrusion 2d is inserted into the stopper portion 1ba, the rotation angle of the annular frame 2 is limited to a predetermined angle by which the protrusion 2d moves from one end to the other in the circumferential direction of the stopper portion 1ba.

[0063] The circumferential length of this stopper portion 1ba should be greater than the maximum distance between the other end 6b of the second elastic member 6 and the recess 2b, for example, the distance S3 described above. By setting the circumferential length of this stopper portion 1ba, the predetermined angle at which the annular frame 2 rotates can be freely set.

[0064] Furthermore, Figure 10 shows a case where the main body 1b is provided with a stopper portion 1ba, but the position of the stopper portion 1ba is not limited to this, and of course, such a stopper may also be provided on the lens mount 1c.

[0065] Next, each embodiment of the notch 2a provided in the annular frame 2 will be described with reference to Figure 11.

[0066] The notch 2a of the annular frame 2 shown in Figures 1 and 3 is formed by linearly cutting out the outer circumference of the annular frame 2 as shown in Figure 11(a). However, in addition to the linear shape of the notch shown in Figure 11(a), it may also be a folded-line shape as shown in Figure 11(b) or an arc-shaped shape as shown in Figure 11(c). Furthermore, as shown in Figure 11(d), a linear notch can be provided between the inner and outer circumferences of the annular frame 2. When the socket 3 is provided in the notch as shown in Figure 11(d), the socket 3 slides within the notch and moves radially when the annular frame 2 rotates.

[0067] Each of the notches shown in Figures 11(a) to 11(d) can enable or disable electrical connection between the socket contact 3a and the lens contact 5a.

[0068] Finally, the projector of the present invention will be explained using Figure 12.

[0069] The present invention relates to an electronic device that modulates a light beam emitted from a light source device according to an image signal and projects it onto a projection surface such as a screen, and further comprises the lens mounting device described above, a light source device that emits a light beam, and an optical modulator that modulates the light beam emitted from the light source device according to an image signal.

[0070] Specifically, as shown in Figure 12, the projector of the present invention includes a light source that emits blue laser light. A portion of the blue laser light from the light source is used as excitation light to excite the yellow phosphor of a phosphor wheel, causing it to emit yellow fluorescence, and yellow light is reflected from the phosphor wheel. This yellow light and the blue light from the blue laser light are combined in a certain ratio to form white light, which is emitted from the light source. The white light from the light source is separated into red, blue, and green light by a dichroic mirror (not shown), and these red, blue, and green lights are incident on an optical modulator such as a liquid crystal panel. The optical modulator modulates the red, blue, and green lights according to the image signal. The modulated color lights are combined in a photosynthesis unit (not shown), such as a prism, to form projected image light. This projected image light is magnified by a lens and then projected onto the projection surface.

[0071] In Figure 12, the lens is a projection lens (lens 5) attached to the projector by the lens mounting device described above. Therefore, in the projector, the volume of the socket can be reduced, poor contact of the socket contacts can be suppressed, and the ease of attaching the lens can be improved.

[0072] The lens mounting device and projector of the present invention have been described above with reference to the specific embodiments shown in Figures 1 to 12.

[0073] As is clear from the above description, the object of the present invention is to provide a lens mounting device that can reduce the volume of the socket, suppress poor contact of the socket contacts, and improve the operability of mounting the lens. To achieve this object, the lens mounting device according to the present invention comprises a base portion 1 having an opening 1a into which a lens 5 is inserted, an annular frame 2 having a notch 2a formed by cutting out a part of the outer circumference, a socket 3 electrically connected to the lens contact 5a as a connection part of the lens 5, and a first elastic member 4 provided to bias the socket 3 from the outer circumference side toward the center of the annular frame 2. The annular frame 2 is rotatably attached to the base portion 1 and is configured to fix the lens 5 inserted into the base portion 1 by rotating it by a predetermined angle in one direction. When the lens 5 is not fixed by the annular frame 2, the notch 2a is in a position that does not face the socket 3, and when the lens 5 is fixed by the annular frame 2, the notch 2a is in a position that faces the socket 3, and the socket 3 is electrically connected to the lens contact 5a of the lens 5 by the biasing force of the first elastic member 4.

[0074] According to the lens mounting device of the present invention, the first elastic member 4 is provided to bias the socket 3 from the outer circumference of the annular frame 2 toward the center, i.e., toward the radial center, so that the effective stroke of the socket contact 3a of the socket 3 is increased and the rate of poor contact at the contact is reduced.

[0075] Furthermore, when the lens 5 is inserted, the socket contact 3a of the socket 3 and the lens contact 5a of the lens 5 do not come into contact, thus preventing the socket contact 3a of the socket 3 from being subjected to impact and deforming.

[0076] Furthermore, since socket 3 does not affect the positioning of lens 5, the position of lens 5 can be precisely determined.

[0077] Furthermore, since lens 5 does not need to be rotated after insertion, the installation of lens 5 is convenient, and the ease of installation is improved, especially for heavier lenses.

[0078] Finally, because socket 3 is radially movable, the socket is small in size and low in cost.

[0079] Preferably, a recess 2b is formed on the inner circumference of the annular frame 2 through which a protrusion 5b provided on the outer surface of the lens 5 is inserted, and a second elastic member 6 is provided on the annular frame 2 at a predetermined distance from one end of the recess 2b, which elastically contacts the protrusion 5b when the annular frame 2 is rotated in one direction, thereby biasing the lens 5 toward the base portion 1.

[0080] Furthermore, it is preferable that a plurality of corresponding protrusions 5b, recesses 2b, and second elastic members 6 are provided, and that the predetermined distance between one end of each recess 2b and the corresponding second elastic member 6 is different.

[0081] Furthermore, it is preferable that the predetermined distance between one end of each recess 2b and the corresponding second elastic member 6 is set such that, when the annular frame 2 is rotated in one direction, each second elastic member 6 and the corresponding protrusion 5b sequentially come into elastic contact.

[0082] This prevents a sudden increase in resistance when the annular frame 2 is rotated, and allows this resistance to be increased gradually, enabling the annular frame 2 to rotate smoothly and preventing deformation or displacement of the annular frame 2.

[0083] The base portion 1 includes the main body 1b and the lens mount 1c, the annular frame 2 is provided between the main body 1b and the lens mount 1c, the lens 5 is inserted into the base portion 1 from the main body 1b side, and the second elastic member 6 preferably elastically contacts the convex portion 5b when the annular frame 2 is rotated in one direction, thereby biasing the lens 5 toward the lens mount 1c side.

[0084] As a result, the gravity of the lens 5 is supported by the main body 1b, and the gravity of the lens 5 hardly acts on the lens mount 1c. Therefore, the lens mount 1c does not need to be very hard and can be made of inexpensive material, leading to cost reduction.

[0085] Preferably, the lens mount 1c is provided with a groove 1ca that houses the protrusion 5b through which the recess 2b is inserted.

[0086] This allows the lens 5 to be easily attached to the base part 1 using this groove 1ca.

[0087] Preferably, the base portion 1 is provided with a stopper portion 1ba for limiting the rotation angle of the annular frame 2 to a predetermined angle.

[0088] As a result, by setting the circumferential length of this stopper portion 1ba, the predetermined angle at which the annular frame 2 rotates can be freely set.

[0089] It is preferable that the lens 5 can be fixed and the electrical connection between the socket contact 3a of the socket 3 and the lens contact 5a of the lens 5 can be released by rotating the annular frame 2 by a predetermined angle in the opposite direction to one direction.

[0090] This allows the lens 5 to be removed from the base 1 with a simple operation: rotating the ring-shaped frame 2 in one direction and the opposite direction.

[0091] Furthermore, the present invention provides a projector characterized by comprising the lens mounting device described above.

[0092] According to the projector of the present invention, since the lens 5 is attached by the lens mounting device described above, the same effects as the lens mounting device described above can be obtained.

[0093] As described above, the present invention fully describes preferred embodiments with reference to the drawings, but of course, those skilled in the art will be able to modify or change these embodiments as appropriate. Such modifications or changes are considered to fall within the scope of protection of the present invention, provided they do not depart from the spirit of the invention. [Explanation of symbols]

[0094] 1. Base section 1a aperture 1b Main body 1ba Stopper part 1c lens mount 1ca groove 2. Ring frame 2a Notch 2b recess 2c Operating lever 2d protrusion 3 sockets 3a Socket contact 4. First elastic member 5 lenses 5a Lens contact 5b Convex part 6. Second elastic member 6a one end 6b Other end

Claims

1. A base portion having an opening into which a lens with a connecting portion is inserted, An annular frame having a notch provided on a part of its outer circumference, A socket electrically connected to the aforementioned lens and the aforementioned connection portion, The socket is provided with a first elastic member that biases the annular frame from the outer circumference toward the center, The annular frame is rotatably attached to the base portion, The annular frame is configured to fix the lens inserted into the base portion by rotating the annular frame by a predetermined angle in one direction. When the annular frame does not fix the lens, the notch does not face the socket. When the annular frame is fixing the lens, the notch faces the socket, and the socket is electrically connected to the connecting portion of the lens by the biasing force of the first elastic member. A lens mounting device characterized by the following features.

2. A base portion having an opening into which a lens with a connecting portion is inserted, An annular frame having a notch provided on a part of its outer circumference, A socket electrically connected to the aforementioned lens and the aforementioned connection portion, The socket is provided with a first elastic member that biases the annular frame from the outer circumference toward the center, The annular frame is rotatably attached to the base portion, The annular frame is configured to fix the lens inserted into the base portion by rotating the annular frame by a predetermined angle in one direction. The annular frame has a recess on its inner circumference through which a protrusion provided on the outer surface of the lens is inserted. The annular frame is provided with a second elastic member located at a predetermined distance from one end of the recess, which elastically contacts the protrusion when the annular frame is rotated in one direction, thereby biasing the lens toward the base portion. The multiple protrusions, the multiple recesses, and the multiple second elastic members are provided in correspondence with each other. The multiple predetermined distances are different from each other. Lens mounting device.

3. The socket is electrically connected to the connecting portion of the lens at a position opposite to the notch of the annular frame. The lens mounting device according to feature 2.

4. The annular frame has a recess on its inner circumference through which a protrusion provided on the outer surface of the lens is inserted. The lens mounting device further comprises a second elastic member located at a predetermined distance from one end of the recess of the annular frame, which elastically contacts the protrusion when the annular frame is rotated in one direction, thereby biasing the lens toward the base portion. The lens mounting device according to feature 1.

5. The multiple protrusions, the multiple recesses, and the multiple second elastic members are provided in correspondence with each other. The multiple predetermined distances are different from each other. The lens mounting device according to feature 4.

6. The plurality of predetermined distances are set so that when the annular frame is rotated in one direction, the plurality of second elastic members and the plurality of protrusions sequentially come into elastic contact. The lens mounting device according to any one of claims 2, 3, and 5.

7. The base portion includes the main body and the lens mount. The annular frame is provided between the main body and the lens mount, The lens is inserted into the base portion from the main body side. The second elastic member elastically contacts the protrusion when the annular frame is rotated in one direction, thereby biasing the lens toward the lens mount. A lens mounting device according to any one of claims 2 to 6.

8. The lens mount has a groove into which the protrusion inserted into the recess is housed. The lens mounting device according to feature 7.

9. The base portion has a stopper portion for limiting the rotation angle of the annular frame to the predetermined angle. A lens mounting device according to any one of claims 1 to 6.

10. The annular frame is configured to release the lens from its fixed position and to disconnect the electrical connection between the socket and the lens by rotating the annular frame by a predetermined angle in the opposite direction to the aforementioned one direction. A lens mounting device according to any one of claims 1 to 6.

11. A projector characterized by comprising a lens mounting device according to any one of claims 1 to 10.

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